Reset mechanism for sensitive relays



April 6, 1954 R. G. QUI-CK 2,674,670

RESET MECHANISM FOR SENSITIVE RELAYS Filed Feb. 14, 1951 IN VEN TOR.

.ROBERT G. QUICK BY jldluuw- ATTKS.

Patented Apr. 6, 1954 RESET MECHANISM FOR SENSITIVE RELAY Robert G. Quick, Silver Spring, Md., assignor to p the United States of America as represented by the Secretary of the Navy Application February 14, 1951, Serial No. 210,904

(Granted under Title 35, U. S. Code (1952),

' sec. 266) 5 Claims.

This invention relates to a new and improved reset mechanism for releasing the pointer of a sensitive relay from its magnetic contact and moving the pointer to the. zero position on the scale of the relay.

The magnetic contact type of relay aforementioned comprises a sensitive moving coil system for displacing a contact arm and moving an iron contact secured to the arm into electrical engagement with one of a pair of spaced stationary permanent magnet contacts. Th magnetic attraction of the stationary contacts supplements the force developed by the moving coil system to insure positive closure of the contacts when the relay has been operated. Power is, therefore, required to separate the'contacts after the contacts have closed. I

One prior art method employed for resetting the contact arm to the zero position comprises an electric solenoid having the end of the solenoid armature arranged to engage th extensions of a pair of reset arms. The reset arms are pivotally mounted on the relay base and are spring urged in opposite directions out of engagement with the contact arm. As the solenoid is energized, the end of the armature slides along the extensions of the reset arms to move the reset arms toward each other and to carry the contact arm away from the magnetic contact and return th contact arm to the zero or neutral setting of the relay. Such a resetting device has not proved to be entirely satisfactory under all conditions of service for the reason that the friction between the armature end and the other extensions of the reset arms causes excessive wear of the parts and consequent failure after prolonged use and the pivot shafts of th reset arms at times have been damaged as a result of inertia shocks received thereby.

According to the arrangement of the present invention the reset'arms are formed of a pair of cantilever springs which are of light weight construction and are flexed or bent by the solenoid armature to move'the contact arm away from the magnetic contact and return it to the zero position.

Thus, in the arrangement of the present invention the delicate pivot shafts of the prior art devices are eliminated from the present device and friction and resulting wear of the various parts of the reset mechanism are greatly reduced. Moreover, a sensitive relay employing the reset mechanismofthe present invention may be subjected to high acceleration and shock without causing damage to the pointer of the relay by iii":

2. action of the reset mechanism in response to inertia forces thereon.

An object oi the invention is to provide a new and improved resetting device of low mass which operates to separate the contact arm of a sensitive relay from its magnetic contact and return the contact arm to the zero position of the relay.

Another object is to provide a resetting mechanism for a magnetic contact type of relay including a solenoid which cooperates with a pair of spring fingers for resetting th contact arm of the relay as the solenoid operates.

A further object is to provide a magnetic contact type relay having a solenoid which operates leaf spring fingers to reset the relay and in which the friction and resulting wear between the solenoid armature and the fingers is materially reduced. 1

Still a further object is to provide a new and 'rnproved reset mechanism for a magnetic type sensitive relay which has a minimum number of parts and a minimum number of points of sliding friction.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. l is a plan view of the relay and the resetting device, some of the parts being broken away;

Fig. 2 is a fragmentary side view of the resetting mechanism, somewhat reduced from the scale of Fig. 1 and some of the parts being broken away to show one of the contact-separating levers; and

Fig. 3 is a view, somewhat reduced, taken along line 3-3 of Fig. 1.

Referring now to the drawings in which like numerals of reference are employed to designate like parts throughout the several views, and more particularly to Fig. 1, there is shown thereon a relay or measuring instrument It having a moving coil II which is angularly displaced about bearing screw l2 in response to the voltage impressed across th instrument. The moving coil ll carries a pointer or contact arm 13 having a soft iron rider it secured thereto which is adapted to move from the zero position it on the insulating scale plate It and into engagement with one of a pair of magnetizedcontactst ll or it according to the direction of the current flow through the coil H. The contacts ll and [8 are supported by mounting brackets l9 which are secured to scale plate I6, and the rider I4 moves in the plane of the contacts I! and I8.

Scale plate I6 is held in parallel relation to base 2! and insulating panel 22 by brackets 23 and 24. Base 2! is threaded for receiving adjusting screw 28 which extends through opening 29 through panel 22. The adjusting screw may be adjusted upward Or downward for lessening or decreasing the length of movement of the armature 26 of solenoid 25. Supported above panel 22 by brackets 23 and 24 is solenoid 25 having an armature 26 pivoted at 21. Th armature 2t has secured thereto a pair of pins 3| which engage the horizontal or operating mid-portions of the formed cantilever springs or resetting levers 32.

Springs 32 are soldered or otherwise secured to brackets 33 which are attached to panel 22 and base 2! by screws 34. The springs are formed in a substantially semi-circular turn or coil at the secured ends thereof and are continued in straight portions 31 which, as best appears in Fig. 3, are engaged by pins 3| and normally di posed parallel to panel 22 and base 2|. Straight spring portions 31 terminate in bends 38 to form obtuse angles between the straight portions 31 and free end portions 39 of the springs, and stiffening or brace members 35 are disposed therebetween and secured thereto as illustrated thereby to provide a truss for maintaining this angular configuration of the springs.

The upper ends of the free spring portions 39 are provided with insulated posts or extensions 36 which form pusher arms for engagement with the contact arm or pointer l3 when the resetting mechanism is operated.

The pusher arm ends or extensions 3% are normally held apart as shown in Figs. 1 and 3 of the drawings by the resilience of springs 32. Upon current flow through the solenoid 25, the

armature 26 and pins 3| move upwardly as viewed in Fig. 3 and carry end posts or extensions 36 toward each other to return the pointer l3 to the neutral or zero position l midway between the contacts I! and 18.

From the foregoing, it should now be apparent that a relay reset mechanism has been provided which is well adapted to fulfill the aforestated objects of the invention.

Obviously many modifications and variations .of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed as new and desired to be secured by Letters Patent of the United States 1s:

1. In a control device comprising a relay including a moving 0011 system carrying a contact arm for movement from a neutral position into magnetic engagement with a stationary contact when the relay is energized, means for resetting said relay to the neutral position comprising a cantilever spring member of arcuate configure-- tion fixed at one end thereof and having a tangential extension thereon, a straight portion extending at an abtuse angle from said tangential portion and'engageable with said contact armfor moving the contact arm from said stationary contact to the neutral position when the spring member is flexed adjacent said fixed end thereof, and an electroresponsive device including an armature having means engageable with said tangential extension of the cantilever spring member for causing an amplified movement of said flexing thereof when the electroresponsive device is energized,

2. An electrical control device comprising means including a moving coil system displaceable in accordance with the direction of current flow through said coil, a pair of spaced contacts, a contact arm carried by said moving coil system and adapted for movement from a neutral position into engagement with either one of said pair of spaced contacts in response to a predetermined degree of movement of the coil system, a pair of independently mounted arcuate spring members having an arcuate portion fixed at one end thereof and a tangential extending portion configurated through an obtuse angle to provide free end portions individual thereto for moving said contact arm away from said one of the contacts engaged therewith and to said neutral position when said spring members are actuated at the tangential portion thereof, and electroresponsive means having an armature, said armature having means engageable with said tangential extension of the cantilever spring member for simultaneous amplified actuation of the spring members when the electroresponsive means is energized.

3. In a sensitive relay of the character disclosed, the combination of a pair of spaced magnetized contacts, a moving coil system displaceable in either direction selectively in accordance with the direction of current flow through said coil, a contact arm carried by said moving coil system and adapted to be moved thereby from a neutral position into engagement with either one of said contacts selectively in accordance with said direction of current flow through said coil, said contact arm carrying a rider thereon of magnetic material and engageable with said one of the contacts for magnetic attraction therewith, a pair of independently mounted cantilever spring members of arcuate configuration and having a tangential portion thereof adapted for actuation to displace an extending portion thereof for separating said contact arm from the contact engaged therewith and for moving the contact arm to said neutral position as the spring members are actuated, said extending portion and said tangential portion being disposed to form an obtuse angle, and a solenoid device including an armature in engagement with the tangential portion of said spring members for simultaneously actuating the spring members when the solenoid device is energized.

4. A control device comprising a base member; primary control means supported on said base member and including a moving coil system, a stationary contact, and a contact arm carried by said coil system for engagement with said stationary contact, said contact being magnetized whereby magnetic attraction is established thereby with said contact arm upon mutual engagement thereof; and means secured to said base member for resetting said primary control means to a neutral position of said contact arm out of engagement with said contact, said resetting means comprising a plurality of independent simultaneously actuated spring members of low mass each having a free end portion engageable with said contact arm, a mid portion, at an obtuse angle with respect thereto and tangential to an arcuate opposite end portion secured in cantilever relation to said base; and a solenoid device including an armature in engagement with said mid portion of each of the spring members for flexing the spring member sufiiciently to separate the contact arm from the contact and move the contact arm to said neutral position when the solenoid device is energized.

5. A control device as claimed in claim 4 further characterized in that said arcuate opposite end portion of the spring member comprises a substantially semi-circular coil disposed in a plane perpendicular to said base, said contact arm is arranged for movement parallel to the base, said armature is arranged for movement substantially perpendicular to the base, and said 6 mid portion extends normally parallel to said base and subtends an obtuse angle with said free end portion of the spring member whereby said free end portion in engagement with the contact arm moves substantially in the path of movement thereof from said contact to said neutral position of the contact arm.

References Cited inthe file of this patent UNITED STATES PATENTS Number Name Date 2,062,915 Lamb Dec. 1, 1936 2,066,514 Beyer et a1. Jan. 5, 1937 2,565,312 Lamb Aug. 21, 1951 2,598,847 Snell June 3 1952 

